A major goal of this study was to explore the diagnostic efficiency of early predictors of PTSD at six months. Participants in this study were initially evaluated within two weeks of visiting an emergency ward for medical care after injuries suffered from physical assault. The participants were again contacted six months later and invited to complete a questionnaire. It was found that the prevalence of acute stress disorder (ASD) was approximately the same as PTSD at six months. Physical scars and pain along with living with someone else were associated with later PTSD. The study did not find that gender and other demographic and traumatic stressors contribute to predict later PTSD. Threats during the assault were related to PTSD at six months and three ASD symptom clusters, dissociation, hypervigilance and functional impairment, predicted later PTSD, together with numbing symptoms. Two important limitations of the study were that the ASD instrument has not established reliability and validity and the diagnoses were based on self-report measures as clinical interviews were not conducted.